The indoor environment of Swedish one-family houses is not subject to any government con-trol. Prior research has shown a connection between an increasing prevalence of allergic dis-ease and an inferior indoor environment. The aim of this study, therefore, is to examine the home-owners’ knowledge of indoor environment and its issues. Furthermore, obstacles and possibilities connected to the improvement of the home-owners’ indoor environment are iden-tified. The study is based on semi-structured interviews with six owners of one-family houses. The result shows that the owners’ general knowledge about indoor environment issues is rela-tively accurate, but that the owners do not always relate this knowledge to their own homes. The obstacles and possibilities towards improving the indoor environment are connected both to knowledge and to economic priorities, and the home-owners’ concerns are often limited to maintenance rather than being directed towards preventive actions. My conclusion is that in order to improve the indoor environment of Swedish one-family houses, it is necessary that the home-owners relate their general knowledge of indoor environment to the circumstances of their own homes. For the home-owners to be able to make that connection, information and education will be needed.